1. Field of the Invention
The present invention relates to a cutting device for breaking fragile materials such as semiconductor wafers or the like and, more particularly, to such a cutting device, which uses lifting, rotary, and feed mechanisms to adjust the position and angle of the diamond cutter, enabling the diamond cutter to scribe and break the workpiece precisely.
2. Description of Related Art
In semiconductor foundries, wafer scribing and breaking apparatus are used to scribe and break 8xe2x80x3 or 12xe2x80x3 semiconductor wafers into individual dies. The cutting tips of cutters for use in wafer scribing and breaking apparatus are commonly made from diamond for the advantage of high hardness. Conventional wafer scribing and breaking apparatus commonly use a rotary mechanism and a feed mechanism to control the cutting position of the diamond cutter relative to the workpiece. This design can simply achieve a coarse manipulation, i.e., the distance between the cutter and the workpiece cannot be precisely controlled, affecting the precision of the scribing of the cutter on the workpiece.
Further, during cutting working of the diamond cutter according to conventional methods, one specific crystal phase position of the diamond cutter is used as the cutting point. This cutting point wears quickly with use. When the cutting point worn out, the diamond cutter becomes useless and must be replaced. When a new diamond cutter installed, the alignment of the newly installed diamond cutter must be calibrated again. It takes time to calibrate the alignment of the loaded diamond cutter. Additionally, it is very hard to manually adjust the angle of the specific crystal phase point of the newly installed diamond cutter to a precise position corresponding to the workpiece.
Therefore, it is desirable to provide a cutting device for breaking fragile materials that eliminates the aforesaid drawbacks.
It is one object of the present invention to provide a cutting device for breaking fragile materials, which uses lifting, rotary, and feed mechanisms to adjust the position and angle of the diamond cutter, enabling the diamond cutter to scribe the workpiece precisely.
It is another object of the present invention to provide a cutting device for breaking fragile materials, which uses a feed mechanism to control the federate of the diamond cutter relative to the fragile workpiece.
It is still another object of the present invention to provide a cutting device for breaking fragile materials, which uses a rotary mechanism to adjust the angle of the diamond cutter, enabling the diamond cutter to scribe the fragile workpiece with one of multiple cutting points thereof.
To achieve these and other objects of the present invention, the cutting device for breaking fragile materials is comprised of a base frame, a lifting mechanism, a rotary table, a cutter holder, and a cutter module. The base frame is installed in a worktable of a wafer scribing and breaking apparatus, having a front mounting face. The lifting mechanism comprises a base block fixedly mounted on the mounting face of the base frame, and a lifting block coupled to the base block for vertical movement on the base block. The rotary table comprises a fixed member fixedly mounted on the lifting block of the lifting mechanism, and a rotary member supported on the fixed member for rotation relative to the fixed member. The rotary member has a front face. The cutter holder is installed in the front face of the rotary member, having a through hole. The through hole has a center axis in parallel to the front face of the rotary member. The cutter module is installed in the through hole of the cutter holder and holding a diamond cutter, comprising a rotary mechanism adapted to rotate the diamond cutter around the center axis of the through hole and a feed mechanism adapted to move the diamond cutter axially along the center axis of the through hole.
By means of the linear or rotary motion of the lifting mechanism, the rotary table and the feed mechanism of the cutter module, the position of the diamond cutter can be precisely adjusted, i.e., the diamond cutter can be shifted vertically through a coarse manipulation of the lifting mechanism, and then rotated to the desired cutting angle on the workpiece, for example, a semiconductor wafer, and then linearly adjusted through a fine micromanipulation of the feed mechanism of the cutter module. Therefore, the relative angle and distance between the diamond cutter and the semiconductor wafer can be adjusted, causing the diamond cutter to scribe the semiconductor wafer precisely.
Furthermore, when the diamond cutter started to wear after long uses, the rotary mechanism is controlled to rotate the diamond cutter through an angle (for example, 90xc2x0), enabling the diamond cutter to cut the workpiece with another crystal phase cutting point. Therefore, the diamond cutter can be rotated to different angular positions to cut the workpiece with different crystal phase cutting points, preventing the occurrence of a precision problem due to a replacement of the diamond cutter.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.